Liverpool legend John Toshack admitted it would be "silly" to bet against Barcelona when they face his old club in the Champions League semi-finals because he believes the Blaugrana are capable of beating anyone when Lionel Messi is playing.

The Reds arrive in Catalonia looking to extend their 19-match unbeaten streak in the first leg of a tie that Toshack said could hinge on the performances of Barcelona's five-time Ballon d'Or winner.

Despite Liverpool's superb form, their former striker refused to back Jurgen Klopp's men to prevail in their quest to reach a second successive Champions League final.

"It is very difficult to bet against Messi," Toshack told AS.com.

"While Messi is playing, you have to be silly to bet against Barcelona. He is capable of beating anyone.

"Messi is something else. He is one of the best, although the best of all time for me will always be John Charles, but I guess that's personal.

"When I see Messi, the first thing I think is: there is no need to train him. A coach is usually very nervous during a game but with Messi, imagine the confidence he gives you. It's incredible."

Toshack added with a cheeky quip: "In golf there is a handicap, and in football there should be a Messi handicap.

"They should give a goal advantage to the opponents when they play against Messi."

The former Real Madrid coach also reminded Liverpool supporters that, while Klopp is already a hero at Anfield, the German coach is yet to win anything with the Reds as he praised Ernesto Valverde's quietly successful approach as Barcelona boss.

Klopp's Liverpool were beaten finalists in the Europa League in his first season on Merseyside, before losing in the Champions League final against Real Madrid two years later.

Valverde has won back-to-back LaLiga titles since his arrival at Barcelona, and Toshack said of him: "I think he's been conservative all his life.

"He was never a star but if he is at Barca, I imagine he has his merits, and not just a few.

"He does not make much noise. And as for Klopp, it's the opposite. But beware Klopp has not won much.

"In Dortmund, yes, but in Liverpool they are waiting for it. In England there are many titles at stake each year and he has not yet won what is expected of him."